1. Field of the Invention
The present invention relates to an air conditioning apparatus provided with a plurality of motor-actuated expansion valves.
2. Description of the Related Art
An air conditioning apparatus is provided with a refrigerating cycle in which a compressor, an outdoor heat exchanger, a pressure reducing device, an indoor heat exchanger, and the like are successively connected to each other by piping. As a refrigerant to be filled into the refrigerating cycle, the R410 refrigerant with high pressure is known. In a high-capacity air conditioning apparatus using the R410 refrigerant, and performing refrigerant flow control of a wide range, it is necessary to employ a large-sized motor-actuated expansion valve (PMV) as a pressure reducing device.
However, a large-sized motor-actuated expansion valve is expensive and leads to an increase in the cost, and hence an air conditioning apparatus using two motor-actuated expansion valves connected in parallel with each other is known (for example, Jpn. Pat. Appln. KOKAI Publication No. 2003-214729).
In such an air conditioning apparatus, when the compressor is stopped, each of the motor-actuated expansion valves is fully closed.
However, when the compressor is stopped, and each of the motor-actuated expansion valves is fully closed, a liquid-sealed state where the refrigerant flow path on the outdoor heat exchanger side is liable to occur. If this liquid-sealed state occurs, there is the possibility of the pressure of the refrigerant collected there being abnormally increased because of an increase in the outside air temperature. If the pressure of the refrigerant is abnormally increased, the components of the refrigerating cycle have been damaged in the worst case.